1. Field of the Invention
The present invention relates to a disk array device, and more particularly to a disk array device for saving power controlled by a controller or a disk.
2. Description of the Related Art
A disk array device is divided into a control enclosure (CE) unit on which communication modules for communicating with device control/higher-order devices are mainly mounted and a disk enclosure (DE) unit on which disks are mounted. When requiring process speed/performance, the number of controllers or the number of CPUs of one controller must be increased or the number of clock frequencies of a CPU must be increased. By this, power consumption also increases. Power consumption also is increased depending on the configuration scale of a disk array. When increasing the amount of data storage, the number of disks must be increased. If the number of disks increases, power consumption increases by the number of disks.    Patent Document 1 discloses a technology for reducing power consumption in a magnetic disk device.    Japanese Patent Application No. H10-333796